This invention relates generally to magnetic resonance imaging, and more particularly the invention relates to motion analysis using motion data, for example as collected using Phase-Contrast (PC) cine Magnetic Resonance Imaging (MRI).
Methods for the calculation of the motion of a material point or a small region during a motion cycle (e.g. the cardiac cycle) are known. The simplest methods assume that the region being analyzed moves as a rigidly translating body. Deformation can be studied by tracking the motion, and specifically the relative motion, of multiple regions. However, the extraction of information may not be ideal since all the motion data samples within a region may not contribute to the results.
A method that allows for deformation and rotation of a region is also known. Typically, the method assumes that the strain within the region being analyzed is homogeneous. The spatial distribution of velocity within the region is assumed to be a linear function, and this allows for homogenous deformation and rotation. In principle, higher order spatial dependence could be allowed, thereby supporting non-homogeneous strain. However, one would then need to decide the degree of heterogeneity to be supported in a particular application. This depends on the object being studied as well as the size of the region.